The hand guard is setup to be semi-monolithic (not quite as nice as DD I think). Take a look at the pics... There's a .045" difference between the Mega upper picatinny rail and the Baer (rail is higher than the upper receiver). I wanted to be able to extend the scope mount (ring) onto the rail so I can get the correct eye relief.

So, when everything is lined up, one ring sits on the upper, the other on the hand guard.

The obvious .045" difference in height between the upper and hand guard will not doubt have an effect on the sighting of the scope. However, do you think this will be a problem both for the scope tube and or maintained accuracy, since the scope now sits with the objective elevated?

The barrel nut is torqued at 75ft-lbs and the hand guard is wedged tightly against the barrel nut jam nut.

Never bridge the gap of a rail and upper. It puts flex stress on your scope and is a great way to damage it.

Prc329

05-29-2009, 6:48 PM

You really need to grab one of these

http://stores.homestead.com/Laruetactical/catalog/P1011738.JPG

eviioiive

05-29-2009, 6:50 PM

Never bridge the gap of a rail and upper. It puts flex stress on your scope and is a great way to damage it.

....esp with the huge step..

goober

05-29-2009, 6:59 PM

Never bridge the gap of a rail and upper. It puts flex stress on your scope and is a great way to damage it.
with independent rings, you're right, not a good idea.
with rings attached to a solid base, or something like an EOTech, not really a problem.
but in this case w/ the big step i'd probably stay away from that too.

parcours

05-29-2009, 7:11 PM

That's what I thought also...

Just didn't look right. Even though the eye relief is where I want it, it's too large of a bridge between the rear and front ring.

I'll either mount both rings on the receiver or get a LaRue mount like the one pictured.

paladin4415

05-29-2009, 7:23 PM

I bet if you match that railed forend with a Baer upper receiver, they will match. I have never measured them myself, but have been told several times by different people that Les's receivers are cut to Les's specs. Those specs don't necessarily match the "standard" specs most companies use.

parcours

05-29-2009, 7:47 PM

I bet if you match that railed forend with a Baer upper receiver, they will match. I have never measured them myself, but have been told several times by different people that Les's receivers are cut to Les's specs. Those specs don't necessarily match the "standard" specs most companies use.

So what do you think about using his upper to build an M4 on a S&W M&P15 lower? I understand that M&P 15 are also not "mil-Spec"... Is that true?

aplinker

05-29-2009, 8:09 PM

That's what I thought also...

Just didn't look right. Even though the eye relief is where I want it, it's too large of a bridge between the rear and front ring.

I'll either mount both rings on the receiver or get a LaRue mount like the one pictured.

Check out Maxicon's 1-piece mount review... it's very helpful.

If you want to save some money, the new PEPR from Burris is a reasonable choice.

paladin4415

05-29-2009, 8:40 PM

So what do you think about using his upper to build an M4 on a S&W M&P15 lower? I understand that M&P 15 are also not "mil-Spec"... Is that true?

To be honest, I think I would keep it all Les Baer or all something else.